Valve seat insert



Feb. 12",l 1952 Illll Vbly embodying the. invention;

Patented Feb. 12, 1952 Curtiss-Wright Delaware Corporation, acorporationof Application July4 11, 1947, seriaiNo. F1602,44?.

This invention relates to valve seat's. .ar idis, particularly directedto` valve seat inserts for. the valves of an internal combustion engine.

The cylinders, cylinder heads, and/or cylinder blocks of an internal,combustion enginebecome quite fhot during engine operation. Actuallythis structure heats up unevenly, probably because the exhaust gases ofeach cylinder dischargethrough a non-symmetrically disposed valve portin its cylinder head and/or cylinder block. As aresult the valves andthe material of the cylinder heads and/or cylinder blocks about thevalve ports do not expand uniformly as the engine heats upv so that ifthe valveseats are rigid with the cylinder heads and/or cylinder blocks,they 'will"distort. from their original circular condition. ,Thisdistortion of the valve seats prevents proper seating of the enginevalves.

. It is an obj ect of this invention to provide a new and improved valveseat insert. capable of conforming to the shape of the valve head eventhough the support for the valve seat insert distorts into anout-of-round condition,

Other objects of the invention will become ap-A parent upon reading theannexed detailed de scription in connection with the drawing in which:

Figure 1 is a sectional view through a cylinder` headvalve port having avalve seat insert assem- Figure 2 is an enlarged view of a vportion ofyFigure 1; and l Figure 3 is an elevational view of the retainer ring ofsaid assembly.

Referring to the drawing, a portionof a cylinder head, indicated atIl),4 is provided with a .valve port` l2 and a valve f4 slidable in avalve guide I6. The valve port. is providedk with a counter-bore I8having a flatbottom20 and within which an annular valve seat, member 221is secured. The valve l4 is provided with avalve head 24 for cooperationwith thevalve seat membern.

The annular valve seat member 22 is'secured inplace Within thelcounter-bore l8'by a two-'p'art'jl retainer ring 26 having flat axiallyspaced side 19 Claims: 1 C1- 25.114161) ing temperatures.

Accordingly theiaxialwidth of the retaining ring is. made slightly widerthan thegroove 36 within which the ring vis to be placed. j The extentto which` the Width of the retainer ring 26 is,made l.to exceed that ofthe groove 36 depends on such factors as the material of said ringandvalve seat; memberc 22 and their operat- Thus thematerial of said re-ltainer ring, and insert memberr should not be stressed beyond theiryield points when the retainer ring 26 is Ydisposed within ther groovek36, In addition the t between .the retainer ring 26 and .groovel'l ofthevalve seat member 22 should remain tight at operating enginetemperatures even thoughthe valve' seat member runs at a highertemperature, and therefore probably expands,.relative to the retainerring.y For example, in amodern high power aircraft engine in which eachvalve seat member groove 36had an axial width of inches and each valveseat member 22Y and its retainer ring 26 were made from a steel alloyconforming to aeronautical materials speciiication No 5700, publishedfbythe Society of Automotive Engineers, it was found satisfactory to malgathe axial Width of the retainer ring approximately .0002 to .0006 inches(preferably .0004 inches) larger ythan said groove -Width. That is theaxial width of the retainer ring 26 was made from .0'7 to .28 percentlarger than the axial width of the groove 30. Obviously thesepercentages mayA vary with the particular heat and corrosion resistantralloy used for the retainer ring 26 and with that used for the valveseatmember'22 as Wellas with other factors.

lAfter the two-part retainer ring 26 is forced into the groove 30, thisvalve seat insert assembly is inserted within and securedv to thecylinder head Ill, within itsl counter-bore I8, by a shrink tbetweenthe'retainer'ring 26 and the cylinder head I0. To this end, the retainerring is made so that, when its tvo halves are tightly pressed" together,the outer diameter of said ring isl slightly largerthan the internaldiameter of the counter'- bore i8. For example with the counterflrzoreI8 havinga diameter of approximately 3l inches, the` outer diameterofthe retainer ring 2 6 is approxiif mately .01 inch larger than saidcounter-bore prior to insertion of said ring within said cylinder head'and `whilesaid ring and cylinder head are at the same temperature; Inorder to secure `the valve seat assembl'yto the' cylinder he ad, said.assembly is cooled and/or' the cylinder head is heatedto' providethenecessary temperature difference so that the'externalv diameter ofthe retainer ringbecomes less than the internal diameter of the cylinderhead counter-bore I. Thereupon the valve seat insert assembly isinserted into and tightly against the bore I8.

The internal diameter of the retainer ring 26 Vis larger than thediameter of the bottom of the external groove 30 in the valve seatmember 22, thereby providing relative radial clearance between theseparts. In addition the outer diameter of the retainer ring 26 is largerthan the adiacent external diameter of the valve seat member 22 by anamount which preferably is equal to or larger thanthis clearnace. Theamount ,of this clearance is not critical and, for example, ,may beabout .02 inch before shinking the valve seat member and retainer ringwithinthe counter-bore I8. .Because of this radialrclearance and sincethe' engaging surfaces of the retaining ring 26 and valve seat member2,21are at, said Vvalve seat memberV can shift radiallvrelative to saidretaining ring and cylinder headlf Accordingly the valve seat member 22does not have Yto conform to the shape of the counterfbore I8 andinstead said valve seat mem- 4 valve seat member 22.

4 22 and its retainer ring 26 remains eiective during engine operation.

The tight i'lt of the retainer ring in the valve seat member groove 36has the further advantage in that this construction results in a goodheat conducting iiow path from the valve seat member 22 to its cylinderhead I0, thereby helping to coolf said valve's'eat member. Also thepresent construction permits the use of a retainer ring 26 of high heatconductivity thereby further helping to reduce the operating temperatureof the In addition, because of a tight iit between thevalve seat member22 and retainer fring26, Asome of the valve loads are transmitted from.the valve seat member 22 to the cylinder head through the retainer ring26 instead of all 'the loads` being transmitted from the `valveseatmember directly to the cylinder head at the bottom 20 of thecounter-bore I 8.

.While ,I'have described my invention in detail in itsvprefslentrpre'ferred embodiment, it Will be obvious toftho'se*`"sl;illedin the art, after understanding iny'inventiomjthatvarious changes and mdica'tionsr'may bejmade therein without de-Vparting from the spiritor scope thereof. I aim in theappended claims to.cover all such modicaber is free to conform to the shapel of the valvehead 24.l Thus.' as the engine heats un, if the cvliinder'head I0ydistorts its counter-bore I 8 to an `#out, -oi-rou'ndA condition, theshrink-fit between the,A retainer "ring 26 and said cylinder head willforce the retainer ring to assume the same outoffrund condition..Howeven because of the radialelearance between the valve seat member 22and retainer ring 26, this distortion is not transmitted to said vvvalveseat member. Also, if the valve heal-24 distorts to an out-oi'roundcondition, theradial clearance between its valve seat member 272 andretainer ring 26. permits the Valve head `24v upon engagement with itsvalve seat member, toforce s a'id valve seat member to conform lto theshape of the Valve head. In addition,V if. as a resultrvof distortion ofthe cylinder hld, thevalve guide I6 should shift relative to the axis'VAofthe counter-bore I 8, the valve seat memberrzz'isfree to shiftaxial1y, upon engagef ment by the valve head 24, so as to center thevalveiseat member relative to the valve guide I6.

One of the difficulties` with prior art valve seatV member "and"retainer ring assemblies, having radialclearance therebetween, hasresulted from leakage of combustion gases between the valve seatk memberand its retainer ring, whereby carbon deposits-,built therebetween todestroy said radial clearance. V- With the present construction, thetightft ofthe,l retainer ring 26 within the groove 36;,qflthef`valveseat member 22 prevents leakage ofcombustion gases between said ring andmember; A lso for ythis purpose, the ends of each half oftheftwoV-partretainer ring 26 are formed so that,V Whensaid Vtwo-part retainer ringisV shrunkv into the counter-bore I8, gas tight joints are provided.between the abutting ends 28 of said ring fh'alves. In addition theouter corners Y 32 and 34 of Vthe groove 30 preferably are madesharpesozthat anycarbon deposits, which may tendto buildup on theportion of the ring 26 pro- 1 J'QQI'S but ofthe groove 30, will bescraped 01T uponvrelatiye radial motion of the valve seat member 22 andretainer ring 26. Inthis way the radial clearancebetween the valveseal?7 mlllhei;

,comprisingy a valve seat rin'g, and a retainer' ring having fa Ashrinkt with the wall of said passage;

. for supportingsaid valveV seat ring in said valve body, one of ,saidrings` having an annular groove which isjiormed bytwozannularaxially-spaced side walls interconnected byfan annular bottoni wallVandiwithn Iwhich the.`other ring extends radiallyfin engagement `withsaid side walls but in rradially-,spaced"relation with said bottom wall,said annulargroove'side walls each being nat and lying in' aplaneperpendicular to the axis of said onering andQhai/ingV asuiiicier'itly tight fit with the eng'ing'suriaCef ofsaid other ring topre Vent gasfleakageftherebetween without lliifevent#l ingradi'almovement of the valve seat riti@ i812* tive to said retainerringand valve body.

2.,I'r i aya'lve "body having a fluid passage` therein with *alcounterbore having an annular ally-$1221. Y

annular groove sid"walls"each being at and ilat bottom surfacedisposedji'ri a plane perpendieul'ar'td'tiie vaxis of said counterbor'e,an ane nular47V valve. seat assembly. secured to said bedy within saidcounterbore, saidas'se'mbly consi-pris-w inga valve ,seat ring, and aretainer ring hav'-I ing a shrink iit with th'evwall/of said counteibordfor supporting saidvalve seat ring in said valve body,y one'ofsaid ringshaving an Aannular fla-tf 'surfacejitted against the flat bottom of saidcounterbo ,and having an annular groove which is formed y twoannularaxially-spaced side Walls inte, onriectedgb'y an annular bottomwall and within which the other ring extends radially iny engagement,with said side walls but in radid relation' with lsaid bottom wall,said lying in afplane perpendicular to the axis of said one ring andVhaving Aa sufficiently tight fit with the Vengaging surfacefof saidother ring to prevent ga'sQleakage therebetween without preventingradial lmovement of the valve seat ring relap tivetoV Saifdretainervringand valve body.

3.7Ir1m a'jyal've body having a fluid passage," there'im an annularValve seat assembly secured @to said body ywithin;said uid passage, saidassenjlbly'"colfnprising:A afvalt/e' seat ring, and al vrealienatetainer ring having'a shrink nt with the wall of said passage forsupporting said valve seat ring in said valve body, said retainer ringcomprising a plurality, of.v individual circular .segments disposed inend-to-end relation tof'orm" a complete ring'enci'rcling said valve seatring, one'of said rings having anannular groove which i'siformed bytwo'v annular axially-spaced side walls inter'- connected by an annularbottom wall and -within which the other ring-extends-radially in engage#ment with said sidewalls but in radially-spaced relation with rsaid-bottom y wall, said annular groove sidewalls each being hat andlyingin--a plane perpendicular to the axis of said one ring an'dha'v'ngasuiciently tight iitl with' the en gagingsurface-cf-said otherv ring toprevent gas leakage therebetween without preventing radial movement ofthe valve seat ring relative to said retainer ring and valve body.

4. In a valve body having a fluid passage therein, an annular valve seatassembly secured to said body within said nuid passage, said assemblycomprising a valve seat ring, and a retainer ring having a shrink t withthe wall of said passage for supporting said valve seat ring in saidvalve body, said retainer ring comprising a plurality of individualcircular segments disposed in end-to-end relation to form a completering encircling said valve seat ring, one of said rings having anannular groove which is formed by two annular axially-spaced side wallsinterconnected by an annular bottom wall and within which the other ringextends radially in engagement with said side walls but inradially-spaced relation with said bottom wall, said annular groove sidewalls and the surfaces of said other ring engaged thereby each beingfiat and lying in a plane perpendicular to the axis of its ring and theflt between said side walls and said other ring being tight withoutpreventing radial movement of the valve seat ring relative to saidretainer ring and valve body.

5. In a valve body having a fluid passage therein with a counterborehaving an annular at bottom surface disposed in a plane perpendicular tothe axis of said ,counterbore, an annular valve seat assembly secured tosaid body Within said counterbore, said assembly comprising a valve seatring, and a retainer ring having a shrink twith the wall of saidcounterbore for supporting said valve seat ring in said valve body, Saidretainer ring comprising a plurality of individual circular segmentsdisposed in end-toend relation to form a complete ring encircling saidvalve seat ring, one of said rings having an annular flat surface fittedagainst the fiat bottom of said counterbore and having an annular groovewhich is formed by two annular axially-spaced side Walls interconnectedby an annular bottom wall and within which the other ring extendsradially in engagement with said side walls but in radially-spacedrelation with said bottom wall, said annular groove side walls and thesurfaces of said other ring engaged thereby each being flat and lying ina plane perpendicular to the axis of its ring and the t between saidside walls and said other ring being sufliciently tight to prevent gasleakage therebetween without preventing radial movement of the valveseat ring relative to said retainer ring and valve body.

, 6. In a valve body having a fluid passage therein with a counterborehaving an annular flat bottom surface disposed in a plane perpendicularto the axis of said counterbore, an annular valve'Vseatassem'l'clyjl'secured `to `'saidt body within said'4 counterlinore,yVsaid assembly comprising a valve seatringja'nd a retainerri'ng`lfravi'ng'a shrink fit withl the wall of saidcounterbore"forrsupporting said 'valve seat ring inI said valve body; said 'retainer'ring l comprising a lplurality 'of-`individualf circular segmentsdisposed `vin endete end relationto'form a completev ring encircling`said valver seat ring, said valve seat ring having' an Vannularflat-surface tted against the' flat bottoml of said counterbore landhaving ari-fana'` nii-lain` outwardly-facing groove *which is 'formedr`by tv/ohannularaxially-spacedfside'walls inter'-V connected byanhannularbottomwallzand within which -saidretainer ring extends vradially in'-wardlyin engagement with said sidewalls but the fit between said grooveside Walls and said retainer ring is such as results from the axialwidth of said retainer ring between its said flat surfaces, before saidretainer ring is placed within said groove, being approximately 0.07 to0.28 percent greater than the axial width of said groove between saidnat groove side walls.

8. In a valve body having a fluid passage therein with a counterborehaving an annular flat bottom surface disposed in a plane perpendicularto the axis of said counterbore, an annular valve seat assembly securedto said body within said counterbore, said assembly comprising a valveseat ring, and a retainer ring having a shrink t with the wall of saidcounterbore for supporting said valve seat ring in said valve body, saidretainer ring comprising a plurality of individual circular segmentsdisposed in end-to-end relation to form a complete ring encircling saidvalve seat ring, said valve seat ring having an annular flat surfacet'ted against the fiat bottom of said counterbore and having an annularoutwardly-1 Y facing groove which is formed by two annular jaxially-spaced side walls interconnected by an annular bottom wall andwithin which said retainer ring extends radially inwardly in engagementwith said side walls but in radially-spaced relation with said bottomwall, said annular groove side walls and the surfaces of said retainerring engaged thereby each being flat and lying in a plane perpendicularto the axis of its ring and the t between said side walls and saidretainer ring being sufficiently tight to prevent gas leakagetherebetween without preventing radial movement of the valve seat ringrelative to said retainer ring and valve body and without stressing thematerial of said rings beyond their yield points.

9. In a valve body having a fluid passage therein with a counterborehaving an annular flat bottom surface disposed in a plane perpendicularto the axis of said counterbore, an annular valve seat assembly securedto said body within said counterbore, said assembly comprising a valveseat ring, and a retainer ring having a shrink t with the wall of saidcounterbore for supporting circular segments disposed in end-to-endrela-` tion to forma complete ring encircling said valve seat ring, saidvalve seat ring having a flat annu-l lar surface tted against the atbottomrof said counterbore and having an annularV outwardlyfacing groovewhich is formed by two annular axially-spaced side walls interconnectedvby an annular bottom Wall and within which said retainer ring extendsradially inwardly in engagement with said side walls but inradially-spaced relation with said bottom wall, the side walls of saidgroove and the annular surfaces of the retainer ring engaged therebyhaving a tight t such as results from said retainer ring having a Widthslightly greater than the axial width of said groove before saidretainer ring is placed in said groove. A Y l' GEORGE H. KELLER.

REFERENCES CITED The following references are of record in the le ofthis patent: v y

UNITED STATES PATENTS Number Name Date 1,435,029 Stewart Nov. 7, 19,221,756,337 Bowler Apr. 29, 1930 1,891,460 Vlahek Dec. 20, 1932 1,949,613McDonald Mar. 6, 1934 1,988,966 Eckhouse Jan. 22, 1935- 2,035,165Jardine Mar. 24, 1936 2,114,934 Nordstrom Apr. 19, 1938 2,179,165Sifkovitz Nov. 7, 1939 2,350,905 Koehler June 6, 1944 .2,366,520Grin-ith Jan. 2, 1945 2,429,778

stanena oct. 28, 1947

